Process for the production of filaments from molten thermoplastic materials



Apnl 18, 1944. E. DUMONT 2,347,035

PROCESS FOR THE PRODUCTION OF FILAMENTS FROM` MOLTEN THERMOPLASTICMATERIAL Filed Aug. 1s. 1940 A Ligen Dum'oz INVENTOR. BY r magQg" H /SATTORNEYS Patented Apr. 18, 1944 unirse s'rsrss PROCESS FOB, THEPRODUCTION F FEA- MENTS FRGM MGLTEN THERMOPLASTC MATERIALS Eugen Dumont,'.iroisdori', near Cologne, Germany; vested in the Alien PropertyCustodian Application August i3, 1940, Serial No. 352.3% A Germany July8, 15.939y

7 Claims.

This invention relates to the production of shaped structures fromreversibly moldable synl thetic resins.

It is known that shaped structure can be produced from synthetic resins.for instance polyd styrol, polyvinyl carbazole, in such a manner, thatfor instance by a drawing process these structures show specialorientation in one direction only and therefore exhibit specialproperties with regard to tenacity and pliability.

According to methods hitherto known it was not possible however toproduce shaped structures, such as laments, rods, tubes and the likeconsisting of preferably linear molecules which exhibit an orientationeffect in several directions. l

It is Lan object of the present invention to manufacture shapedstructures-from reversibly moldable synthetic resins.

A further object is to produce by special niechanical means anorientation eiiect of therresins in diierent directions, therebyimproving the tenacity of the products.

These and other objects will become apparent :from the followingspecication.

The present invention is based on the observation, that it is possibleto manufacture shaped structures, such as laments, rods, tubes and thelike by extruding them in a plastic, molten liquid or dissolved statefrom a nozzle rotating 3 quickly around its axis, and linally colddrawing said structures in the direction of the extrusion. In this way`simply shaped structures such as laments, rods, tubes and the like showan orientation eect in several directions which greatly improves thetenacity of the product.

.The additional drawing of the structure extruded from the nozzle ispreferably accomplished in such a manner that the extruded lament iswound up on a cylinder or roll or on other suitable rotating means, theperipheral speed of which, however, is higher than the speed at whichthe filament is discharged from the nozzle.

The drawing of the filament being extruded from the nozzle may beaccomplished according to the present invention also in such a Waythatthe lament is passed between several pairs of rolls or cylinderssuccessively, the speed of rotation of successive pairs of rolls beinggreater than that of the. preceding pair. occurs hereby wherein thedrawing force may gradually decrease vfrom step to step. By these meansan enhanced drawing efect of the nal product and correspondingly ahigher orientation eiect is obtained.'

Repeated drawing (Cl. 18nd@ Reference is made to the accompanyingdrawing in which v l Figure 1 is a diagrammatic view of an extrudingdevice `using a cylinder to wind up the vfilament. I

-Figure 2 represents mechanical drawing means in which there are used aplurality of cylinder groups, .between which the extruded filamentpasses.

The lament c consisting of thermoplastic synthetic resins and beingextruded from the nozzle b which rotates in the bearings a is wound upin coils on a cylinder d. Said cylinder rotates in the bearings e with ahigher` peripheral speed than the corresponding extrusion'velocity.

According to Figure 2 the lament c leaves the rotating nozzle b, passesin between the cylinder groups f, g, h and is finally wound up on a rollt. These cylinders f, i7, h and the roll i are driven with a peripheralspeed increasing from' the nozzle-opening towards the cylinder i,wherelby the peripheral speed of the cylinder f is higher than theextrusion velocity of ilament c. Gradual drawing of the lament or tubeis therefore attained between the nozzle-opening and the cylinder groupas well as between the cylinder roups f, y, h and the cylinder grouphand cylinder i. By this drawing action in connection with the torsioncaused by the rotating nozzle 0 there is accomplished an orientationeffect which is characterized by a considerably improved tev nacity ofthe particular products. y

According to the present invention there may ybe worked up all syntheticresins possessing prefs erably a linear structure of the polymericmolecules. To these synthetic products there belong especially thepolymerisates or interpolymerisates of vinyl chloride, vinyl acetate,Vinyl alcohol, vinyl carbazole, maleic acid anhydride and simio .l'arcompounds. By the present invention there is attained on all thesematerials an orientation effect which greatly improves their tenacity.'

This is especially true of the superpoly-condensates which according tothis invention represent a most suitable material, such as thesuperpolyamldes and polyamide condensation products which are obtainableeither from dibasic acids and diamines or from aminocarboxylic acids andtheir lactams.

What I claim is:

1. A process for the production oi filaments from va moltenthermoplastic filament-forming mass comprising the steps of extrudingthe said mass through an axial oriil'ce of a. nozzle which is rotatedabout its longitudinal axis and which twistsv the eztrudate and thenlengthwise cold drawing the twisted extrudate by drawing the same fromthe said nozzle at a speed greater than the speed at which it isextruded.

2. A process for the production of filaments i fronra moltenthermoplastic filament-forming4 mass consisting of the steps oiextruding the said mass through an axial oriilce of a rotating nozzleand stretching the extrudate by cold drawing the same from said nozzleat a speed greater than the speed at which it is extruded by engagementof the extrudate with a cylinder, the peripheral speed of which isgreater than the extrusion speed.

3. A process for theproduction of filaments from a molten thermoplasticfilament-forming mass consisting of the steps of extruding the,

said mass through an axial oriilce of a rotating nozzle and stretchingthe extrudate by cold drawing the same from said nozzle at a speedgreater than the speed at which it is extruded.

-by engagement of the extrudate with a cylinder,

the peripheral speed of which is greater than the extrusion speed, andthen 'winding the extrudate upon a cylinder having a peripheral 25vinylacetate.

speed greater than said first named cylinder.

4. A process i'or the'production of filaments from a moltenthermoplastic lament-forming mass consisting of the steps-of extrudingthe said .mass through an axial oriilce of a nozzle which 5 is rotatedabout its longitudinal axis and which twists the extrudate and thenlengthwise cold Adrawing the .twisted extrudate by passing it betweensuccessive pairs of rotating cylinders while insuring engagement of thetwisted extru- 10 date with the nips formed by each pair of saidcylinders, causing the cylinders of the first pair to rotate at a speedgreater than that at which the extrudate is extruded from the nozzle andgiving to the cylinders of each succeeding pair 1s a speed of rotationwhich is greater than that of the cylinders of each preceding pair.

5. The process as defined in claim l wherein the thermoplastic illamentforming mass is a EUGEN DUMONT.

